In food production, in particular in meat and sausage production, several individual apparatuses whose functions must be matched are provided in a production line. In process data transmission for Ethernet-based field bus systems, up to now conventional cables and plugs have been used, as is represented, for example, in FIG. 17. Cables and plugs often involve malfunctions, standstills and failures in machines in rough surroundings.
In case of electric pin-and-socket connectors, in particular the connector pin and the associated socket contact are, in an unplugged condition, susceptible to mechanical damage, soiling and corrosion. In most commercially available pin-and-socket connectors, even water or cleansing chemicals may penetrate through the pin-and-socket connector into the cable when the connector is not plugged in, causing severe damage to the cable by corrosion. The transition from the connector pin or socket contact to the cable is also very liable to oxidation due to the different materials. This will then lead to high transition resistances and leakage currents.
As an alternative for process data transmission by means of cables, data transmission by means of WLAN or Bluetooth is also employed at present.
However, this solution, too, involves disadvantages in that it is relatively slow compared to cable connections and mainly susceptible to radio interferences. Moreover, there is a disadvantage, in particular when several transmitters are provided, in that the receiver must be tuned to the desired station involving considerable configuration efforts and also sources for errors. Only a few radio frequencies are available. If several transmitters and receivers are operated within the transmission range, interferences by adjacent transmitters occur. The bandwidth must be shared with other apparatuses. If the available bandwidth is not sufficient, the apparatuses may not be operated simultaneously. A matching radio channel must be selected and adjusted. The temporal division of the transmission capacity is also relevant, so that one has to wait for free channels, and moreover, the repetition of transmission in case of an interfered reception takes some time. Changing the channel if interferences occur again also takes time. Moreover, it may not be predicted how long a successful transmission will take. Altogether, process data transmission in real time cannot be performed.